Merge branch 'jellyfin:master' into master

1 files changed, 586 insertions, 0 deletions

diff --git a/Jellyfin.Api/Controllers/VideoHlsController.cs b/Jellyfin.Api/Controllers/VideoHlsController.cs
new file mode 100644
index 000000000..ef25db8c9
--- /dev/null
+++ b/Jellyfin.Api/Controllers/VideoHlsController.cs
@@ -0,0 +1,586 @@
+using System;
+using System.Collections.Generic;
+using System.ComponentModel.DataAnnotations;
+using System.Globalization;
+using System.IO;
+using System.Threading;
+using System.Threading.Tasks;
+using Jellyfin.Api.Attributes;
+using Jellyfin.Api.Constants;
+using Jellyfin.Api.Helpers;
+using Jellyfin.Api.Models.PlaybackDtos;
+using Jellyfin.Api.Models.StreamingDtos;
+using MediaBrowser.Common.Configuration;
+using MediaBrowser.Controller.Configuration;
+using MediaBrowser.Controller.Devices;
+using MediaBrowser.Controller.Dlna;
+using MediaBrowser.Controller.Library;
+using MediaBrowser.Controller.MediaEncoding;
+using MediaBrowser.Controller.Net;
+using MediaBrowser.Model.Configuration;
+using MediaBrowser.Model.Dlna;
+using MediaBrowser.Model.Net;
+using Microsoft.AspNetCore.Authorization;
+using Microsoft.AspNetCore.Http;
+using Microsoft.AspNetCore.Mvc;
+using Microsoft.Extensions.Logging;
+
+namespace Jellyfin.Api.Controllers
+{
+    /// <summary>
+    /// The video hls controller.
+    /// </summary>
+    [Route("")]
+    [Authorize(Policy = Policies.DefaultAuthorization)]
+    public class VideoHlsController : BaseJellyfinApiController
+    {
+        private const string DefaultEncoderPreset = "superfast";
+        private const TranscodingJobType TranscodingJobType = MediaBrowser.Controller.MediaEncoding.TranscodingJobType.Hls;
+
+        private readonly EncodingHelper _encodingHelper;
+        private readonly IDlnaManager _dlnaManager;
+        private readonly IAuthorizationContext _authContext;
+        private readonly IUserManager _userManager;
+        private readonly ILibraryManager _libraryManager;
+        private readonly IMediaSourceManager _mediaSourceManager;
+        private readonly IServerConfigurationManager _serverConfigurationManager;
+        private readonly IMediaEncoder _mediaEncoder;
+        private readonly IDeviceManager _deviceManager;
+        private readonly TranscodingJobHelper _transcodingJobHelper;
+        private readonly ILogger<VideoHlsController> _logger;
+        private readonly EncodingOptions _encodingOptions;
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="VideoHlsController"/> class.
+        /// </summary>
+        /// <param name="mediaEncoder">Instance of the <see cref="IMediaEncoder"/> interface.</param>
+        /// <param name="dlnaManager">Instance of the <see cref="IDlnaManager"/> interface.</param>
+        /// <param name="userManger">Instance of the <see cref="IUserManager"/> interface.</param>
+        /// <param name="authorizationContext">Instance of the <see cref="IAuthorizationContext"/> interface.</param>
+        /// <param name="libraryManager">Instance of the <see cref="ILibraryManager"/> interface.</param>
+        /// <param name="mediaSourceManager">Instance of the <see cref="IMediaSourceManager"/> interface.</param>
+        /// <param name="serverConfigurationManager">Instance of the <see cref="IServerConfigurationManager"/> interface.</param>
+        /// <param name="deviceManager">Instance of the <see cref="IDeviceManager"/> interface.</param>
+        /// <param name="transcodingJobHelper">The <see cref="TranscodingJobHelper"/> singleton.</param>
+        /// <param name="logger">Instance of the <see cref="ILogger{VideoHlsController}"/>.</param>
+        /// <param name="encodingHelper">Instance of <see cref="EncodingHelper"/>.</param>
+        public VideoHlsController(
+            IMediaEncoder mediaEncoder,
+            IDlnaManager dlnaManager,
+            IUserManager userManger,
+            IAuthorizationContext authorizationContext,
+            ILibraryManager libraryManager,
+            IMediaSourceManager mediaSourceManager,
+            IServerConfigurationManager serverConfigurationManager,
+            IDeviceManager deviceManager,
+            TranscodingJobHelper transcodingJobHelper,
+            ILogger<VideoHlsController> logger,
+            EncodingHelper encodingHelper)
+        {
+            _dlnaManager = dlnaManager;
+            _authContext = authorizationContext;
+            _userManager = userManger;
+            _libraryManager = libraryManager;
+            _mediaSourceManager = mediaSourceManager;
+            _serverConfigurationManager = serverConfigurationManager;
+            _mediaEncoder = mediaEncoder;
+            _deviceManager = deviceManager;
+            _transcodingJobHelper = transcodingJobHelper;
+            _logger = logger;
+            _encodingHelper = encodingHelper;
+
+            _encodingOptions = serverConfigurationManager.GetEncodingOptions();
+        }
+
+        /// <summary>
+        /// Gets a hls live stream.
+        /// </summary>
+        /// <param name="itemId">The item id.</param>
+        /// <param name="container">The audio container.</param>
+        /// <param name="static">Optional. If true, the original file will be streamed statically without any encoding. Use either no url extension or the original file extension. true/false.</param>
+        /// <param name="params">The streaming parameters.</param>
+        /// <param name="tag">The tag.</param>
+        /// <param name="deviceProfileId">Optional. The dlna device profile id to utilize.</param>
+        /// <param name="playSessionId">The play session id.</param>
+        /// <param name="segmentContainer">The segment container.</param>
+        /// <param name="segmentLength">The segment lenght.</param>
+        /// <param name="minSegments">The minimum number of segments.</param>
+        /// <param name="mediaSourceId">The media version id, if playing an alternate version.</param>
+        /// <param name="deviceId">The device id of the client requesting. Used to stop encoding processes when needed.</param>
+        /// <param name="audioCodec">Optional. Specify a audio codec to encode to, e.g. mp3. If omitted the server will auto-select using the url's extension. Options: aac, mp3, vorbis, wma.</param>
+        /// <param name="enableAutoStreamCopy">Whether or not to allow automatic stream copy if requested values match the original source. Defaults to true.</param>
+        /// <param name="allowVideoStreamCopy">Whether or not to allow copying of the video stream url.</param>
+        /// <param name="allowAudioStreamCopy">Whether or not to allow copying of the audio stream url.</param>
+        /// <param name="breakOnNonKeyFrames">Optional. Whether to break on non key frames.</param>
+        /// <param name="audioSampleRate">Optional. Specify a specific audio sample rate, e.g. 44100.</param>
+        /// <param name="maxAudioBitDepth">Optional. The maximum audio bit depth.</param>
+        /// <param name="audioBitRate">Optional. Specify an audio bitrate to encode to, e.g. 128000. If omitted this will be left to encoder defaults.</param>
+        /// <param name="audioChannels">Optional. Specify a specific number of audio channels to encode to, e.g. 2.</param>
+        /// <param name="maxAudioChannels">Optional. Specify a maximum number of audio channels to encode to, e.g. 2.</param>
+        /// <param name="profile">Optional. Specify a specific an encoder profile (varies by encoder), e.g. main, baseline, high.</param>
+        /// <param name="level">Optional. Specify a level for the encoder profile (varies by encoder), e.g. 3, 3.1.</param>
+        /// <param name="framerate">Optional. A specific video framerate to encode to, e.g. 23.976. Generally this should be omitted unless the device has specific requirements.</param>
+        /// <param name="maxFramerate">Optional. A specific maximum video framerate to encode to, e.g. 23.976. Generally this should be omitted unless the device has specific requirements.</param>
+        /// <param name="copyTimestamps">Whether or not to copy timestamps when transcoding with an offset. Defaults to false.</param>
+        /// <param name="startTimeTicks">Optional. Specify a starting offset, in ticks. 1 tick = 10000 ms.</param>
+        /// <param name="width">Optional. The fixed horizontal resolution of the encoded video.</param>
+        /// <param name="height">Optional. The fixed vertical resolution of the encoded video.</param>
+        /// <param name="videoBitRate">Optional. Specify a video bitrate to encode to, e.g. 500000. If omitted this will be left to encoder defaults.</param>
+        /// <param name="subtitleStreamIndex">Optional. The index of the subtitle stream to use. If omitted no subtitles will be used.</param>
+        /// <param name="subtitleMethod">Optional. Specify the subtitle delivery method.</param>
+        /// <param name="maxRefFrames">Optional.</param>
+        /// <param name="maxVideoBitDepth">Optional. The maximum video bit depth.</param>
+        /// <param name="requireAvc">Optional. Whether to require avc.</param>
+        /// <param name="deInterlace">Optional. Whether to deinterlace the video.</param>
+        /// <param name="requireNonAnamorphic">Optional. Whether to require a non anamorphic stream.</param>
+        /// <param name="transcodingMaxAudioChannels">Optional. The maximum number of audio channels to transcode.</param>
+        /// <param name="cpuCoreLimit">Optional. The limit of how many cpu cores to use.</param>
+        /// <param name="liveStreamId">The live stream id.</param>
+        /// <param name="enableMpegtsM2TsMode">Optional. Whether to enable the MpegtsM2Ts mode.</param>
+        /// <param name="videoCodec">Optional. Specify a video codec to encode to, e.g. h264. If omitted the server will auto-select using the url's extension. Options: h265, h264, mpeg4, theora, vp8, vp9, vpx (deprecated), wmv.</param>
+        /// <param name="subtitleCodec">Optional. Specify a subtitle codec to encode to.</param>
+        /// <param name="transcodeReasons">Optional. The transcoding reason.</param>
+        /// <param name="audioStreamIndex">Optional. The index of the audio stream to use. If omitted the first audio stream will be used.</param>
+        /// <param name="videoStreamIndex">Optional. The index of the video stream to use. If omitted the first video stream will be used.</param>
+        /// <param name="context">Optional. The <see cref="EncodingContext"/>.</param>
+        /// <param name="streamOptions">Optional. The streaming options.</param>
+        /// <param name="maxWidth">Optional. The max width.</param>
+        /// <param name="maxHeight">Optional. The max height.</param>
+        /// <param name="enableSubtitlesInManifest">Optional. Whether to enable subtitles in the manifest.</param>
+        /// <response code="200">Hls live stream retrieved.</response>
+        /// <returns>A <see cref="FileResult"/> containing the hls file.</returns>
+        [HttpGet("Videos/{itemId}/live.m3u8")]
+        [ProducesResponseType(StatusCodes.Status200OK)]
+        [ProducesPlaylistFile]
+        public async Task<ActionResult> GetLiveHlsStream(
+            [FromRoute, Required] Guid itemId,
+            [FromQuery] string? container,
+            [FromQuery] bool? @static,
+            [FromQuery] string? @params,
+            [FromQuery] string? tag,
+            [FromQuery] string? deviceProfileId,
+            [FromQuery] string? playSessionId,
+            [FromQuery] string? segmentContainer,
+            [FromQuery] int? segmentLength,
+            [FromQuery] int? minSegments,
+            [FromQuery] string? mediaSourceId,
+            [FromQuery] string? deviceId,
+            [FromQuery] string? audioCodec,
+            [FromQuery] bool? enableAutoStreamCopy,
+            [FromQuery] bool? allowVideoStreamCopy,
+            [FromQuery] bool? allowAudioStreamCopy,
+            [FromQuery] bool? breakOnNonKeyFrames,
+            [FromQuery] int? audioSampleRate,
+            [FromQuery] int? maxAudioBitDepth,
+            [FromQuery] int? audioBitRate,
+            [FromQuery] int? audioChannels,
+            [FromQuery] int? maxAudioChannels,
+            [FromQuery] string? profile,
+            [FromQuery] string? level,
+            [FromQuery] float? framerate,
+            [FromQuery] float? maxFramerate,
+            [FromQuery] bool? copyTimestamps,
+            [FromQuery] long? startTimeTicks,
+            [FromQuery] int? width,
+            [FromQuery] int? height,
+            [FromQuery] int? videoBitRate,
+            [FromQuery] int? subtitleStreamIndex,
+            [FromQuery] SubtitleDeliveryMethod? subtitleMethod,
+            [FromQuery] int? maxRefFrames,
+            [FromQuery] int? maxVideoBitDepth,
+            [FromQuery] bool? requireAvc,
+            [FromQuery] bool? deInterlace,
+            [FromQuery] bool? requireNonAnamorphic,
+            [FromQuery] int? transcodingMaxAudioChannels,
+            [FromQuery] int? cpuCoreLimit,
+            [FromQuery] string? liveStreamId,
+            [FromQuery] bool? enableMpegtsM2TsMode,
+            [FromQuery] string? videoCodec,
+            [FromQuery] string? subtitleCodec,
+            [FromQuery] string? transcodeReasons,
+            [FromQuery] int? audioStreamIndex,
+            [FromQuery] int? videoStreamIndex,
+            [FromQuery] EncodingContext? context,
+            [FromQuery] Dictionary<string, string> streamOptions,
+            [FromQuery] int? maxWidth,
+            [FromQuery] int? maxHeight,
+            [FromQuery] bool? enableSubtitlesInManifest)
+        {
+            VideoRequestDto streamingRequest = new VideoRequestDto
+            {
+                Id = itemId,
+                Container = container,
+                Static = @static ?? false,
+                Params = @params,
+                Tag = tag,
+                DeviceProfileId = deviceProfileId,
+                PlaySessionId = playSessionId,
+                SegmentContainer = segmentContainer,
+                SegmentLength = segmentLength,
+                MinSegments = minSegments,
+                MediaSourceId = mediaSourceId,
+                DeviceId = deviceId,
+                AudioCodec = audioCodec,
+                EnableAutoStreamCopy = enableAutoStreamCopy ?? true,
+                AllowAudioStreamCopy = allowAudioStreamCopy ?? true,
+                AllowVideoStreamCopy = allowVideoStreamCopy ?? true,
+                BreakOnNonKeyFrames = breakOnNonKeyFrames ?? false,
+                AudioSampleRate = audioSampleRate,
+                MaxAudioChannels = maxAudioChannels,
+                AudioBitRate = audioBitRate,
+                MaxAudioBitDepth = maxAudioBitDepth,
+                AudioChannels = audioChannels,
+                Profile = profile,
+                Level = level,
+                Framerate = framerate,
+                MaxFramerate = maxFramerate,
+                CopyTimestamps = copyTimestamps ?? false,
+                StartTimeTicks = startTimeTicks,
+                Width = width,
+                Height = height,
+                VideoBitRate = videoBitRate,
+                SubtitleStreamIndex = subtitleStreamIndex,
+                SubtitleMethod = subtitleMethod ?? SubtitleDeliveryMethod.Encode,
+                MaxRefFrames = maxRefFrames,
+                MaxVideoBitDepth = maxVideoBitDepth,
+                RequireAvc = requireAvc ?? false,
+                DeInterlace = deInterlace ?? false,
+                RequireNonAnamorphic = requireNonAnamorphic ?? false,
+                TranscodingMaxAudioChannels = transcodingMaxAudioChannels,
+                CpuCoreLimit = cpuCoreLimit,
+                LiveStreamId = liveStreamId,
+                EnableMpegtsM2TsMode = enableMpegtsM2TsMode ?? false,
+                VideoCodec = videoCodec,
+                SubtitleCodec = subtitleCodec,
+                TranscodeReasons = transcodeReasons,
+                AudioStreamIndex = audioStreamIndex,
+                VideoStreamIndex = videoStreamIndex,
+                Context = context ?? EncodingContext.Streaming,
+                StreamOptions = streamOptions,
+                MaxHeight = maxHeight,
+                MaxWidth = maxWidth,
+                EnableSubtitlesInManifest = enableSubtitlesInManifest ?? true
+            };
+
+            // CTS lifecycle is managed internally.
+            var cancellationTokenSource = new CancellationTokenSource();
+            // Due to CTS.Token calling ThrowIfDisposed (https://github.com/dotnet/runtime/issues/29970) we have to "cache" the token
+            // since it gets disposed when ffmpeg exits
+            var cancellationToken = cancellationTokenSource.Token;
+            using var state = await StreamingHelpers.GetStreamingState(
+                    streamingRequest,
+                    Request,
+                    _authContext,
+                    _mediaSourceManager,
+                    _userManager,
+                    _libraryManager,
+                    _serverConfigurationManager,
+                    _mediaEncoder,
+                    _encodingHelper,
+                    _dlnaManager,
+                    _deviceManager,
+                    _transcodingJobHelper,
+                    TranscodingJobType,
+                    cancellationToken)
+                .ConfigureAwait(false);
+
+            TranscodingJobDto? job = null;
+            var playlistPath = Path.ChangeExtension(state.OutputFilePath, ".m3u8");
+
+            if (!System.IO.File.Exists(playlistPath))
+            {
+                var transcodingLock = _transcodingJobHelper.GetTranscodingLock(playlistPath);
+                await transcodingLock.WaitAsync(cancellationToken).ConfigureAwait(false);
+                try
+                {
+                    if (!System.IO.File.Exists(playlistPath))
+                    {
+                        // If the playlist doesn't already exist, startup ffmpeg
+                        try
+                        {
+                            job = await _transcodingJobHelper.StartFfMpeg(
+                                    state,
+                                    playlistPath,
+                                    GetCommandLineArguments(playlistPath, state),
+                                    Request,
+                                    TranscodingJobType,
+                                    cancellationTokenSource)
+                                .ConfigureAwait(false);
+                            job.IsLiveOutput = true;
+                        }
+                        catch
+                        {
+                            state.Dispose();
+                            throw;
+                        }
+
+                        minSegments = state.MinSegments;
+                        if (minSegments > 0)
+                        {
+                            await HlsHelpers.WaitForMinimumSegmentCount(playlistPath, minSegments, _logger, cancellationToken).ConfigureAwait(false);
+                        }
+                    }
+                }
+                finally
+                {
+                    transcodingLock.Release();
+                }
+            }
+
+            job ??= _transcodingJobHelper.OnTranscodeBeginRequest(playlistPath, TranscodingJobType);
+
+            if (job != null)
+            {
+                _transcodingJobHelper.OnTranscodeEndRequest(job);
+            }
+
+            var playlistText = HlsHelpers.GetLivePlaylistText(playlistPath, state);
+
+            return Content(playlistText, MimeTypes.GetMimeType("playlist.m3u8"));
+        }
+
+        /// <summary>
+        /// Gets the command line arguments for ffmpeg.
+        /// </summary>
+        /// <param name="outputPath">The output path of the file.</param>
+        /// <param name="state">The <see cref="StreamState"/>.</param>
+        /// <returns>The command line arguments as a string.</returns>
+        private string GetCommandLineArguments(string outputPath, StreamState state)
+        {
+            var videoCodec = _encodingHelper.GetVideoEncoder(state, _encodingOptions);
+            var threads = EncodingHelper.GetNumberOfThreads(state, _encodingOptions, videoCodec); // GetNumberOfThreads is static.
+            var inputModifier = _encodingHelper.GetInputModifier(state, _encodingOptions);
+            var mapArgs = state.IsOutputVideo ? _encodingHelper.GetMapArgs(state) : string.Empty;
+
+            var directory = Path.GetDirectoryName(outputPath) ?? throw new ArgumentException($"Provided path ({outputPath}) is not valid.", nameof(outputPath));
+            var outputFileNameWithoutExtension = Path.GetFileNameWithoutExtension(outputPath);
+            var outputPrefix = Path.Combine(directory, outputFileNameWithoutExtension);
+            var outputExtension = EncodingHelper.GetSegmentFileExtension(state.Request.SegmentContainer);
+            var outputTsArg = outputPrefix + "%d" + outputExtension;
+
+            var segmentFormat = outputExtension.TrimStart('.');
+            if (string.Equals(segmentFormat, "ts", StringComparison.OrdinalIgnoreCase))
+            {
+                segmentFormat = "mpegts";
+            }
+            else if (string.Equals(segmentFormat, "mp4", StringComparison.OrdinalIgnoreCase))
+            {
+                var outputFmp4HeaderArg = string.Empty;
+                if (OperatingSystem.IsWindows())
+                {
+                    // on Windows, the path of fmp4 header file needs to be configured
+                    outputFmp4HeaderArg = " -hls_fmp4_init_filename \"" + outputPrefix + "-1" + outputExtension + "\"";
+                }
+                else
+                {
+                    // on Linux/Unix, ffmpeg generate fmp4 header file to m3u8 output folder
+                    outputFmp4HeaderArg = " -hls_fmp4_init_filename \"" + outputFileNameWithoutExtension + "-1" + outputExtension + "\"";
+                }
+
+                segmentFormat = "fmp4" + outputFmp4HeaderArg;
+            }
+            else
+            {
+                _logger.LogError("Invalid HLS segment container: {SegmentFormat}", segmentFormat);
+            }
+
+            var maxMuxingQueueSize = _encodingOptions.MaxMuxingQueueSize > 128
+                ? _encodingOptions.MaxMuxingQueueSize.ToString(CultureInfo.InvariantCulture)
+                : "128";
+
+            var baseUrlParam = string.Format(
+                CultureInfo.InvariantCulture,
+                "\"hls/{0}/\"",
+                Path.GetFileNameWithoutExtension(outputPath));
+
+            return string.Format(
+                    CultureInfo.InvariantCulture,
+                    "{0} {1} -map_metadata -1 -map_chapters -1 -threads {2} {3} {4} {5} -copyts -avoid_negative_ts disabled -max_muxing_queue_size {6} -f hls -max_delay 5000000 -hls_time {7} -hls_segment_type {8} -start_number 0 -hls_base_url {9} -hls_playlist_type event -hls_segment_filename \"{10}\" -y \"{11}\"",
+                    inputModifier,
+                    _encodingHelper.GetInputArgument(state, _encodingOptions),
+                    threads,
+                    mapArgs,
+                    GetVideoArguments(state),
+                    GetAudioArguments(state),
+                    maxMuxingQueueSize,
+                    state.SegmentLength.ToString(CultureInfo.InvariantCulture),
+                    segmentFormat,
+                    baseUrlParam,
+                    outputTsArg,
+                    outputPath).Trim();
+        }
+
+        /// <summary>
+        /// Gets the audio arguments for transcoding.
+        /// </summary>
+        /// <param name="state">The <see cref="StreamState"/>.</param>
+        /// <returns>The command line arguments for audio transcoding.</returns>
+        private string GetAudioArguments(StreamState state)
+        {
+            if (state.AudioStream == null)
+            {
+                return string.Empty;
+            }
+
+            var audioCodec = _encodingHelper.GetAudioEncoder(state);
+
+            if (!state.IsOutputVideo)
+            {
+                if (EncodingHelper.IsCopyCodec(audioCodec))
+                {
+                    var bitStreamArgs = EncodingHelper.GetAudioBitStreamArguments(state, state.Request.SegmentContainer, state.MediaSource.Container);
+
+                    return "-acodec copy -strict -2" + bitStreamArgs;
+                }
+
+                var audioTranscodeParams = string.Empty;
+
+                audioTranscodeParams += "-acodec " + audioCodec;
+
+                if (state.OutputAudioBitrate.HasValue)
+                {
+                    audioTranscodeParams += " -ab " + state.OutputAudioBitrate.Value.ToString(CultureInfo.InvariantCulture);
+                }
+
+                if (state.OutputAudioChannels.HasValue)
+                {
+                    audioTranscodeParams += " -ac " + state.OutputAudioChannels.Value.ToString(CultureInfo.InvariantCulture);
+                }
+
+                if (state.OutputAudioSampleRate.HasValue)
+                {
+                    audioTranscodeParams += " -ar " + state.OutputAudioSampleRate.Value.ToString(CultureInfo.InvariantCulture);
+                }
+
+                audioTranscodeParams += " -vn";
+                return audioTranscodeParams;
+            }
+
+            if (EncodingHelper.IsCopyCodec(audioCodec))
+            {
+                var bitStreamArgs = EncodingHelper.GetAudioBitStreamArguments(state, state.Request.SegmentContainer, state.MediaSource.Container);
+
+                return "-acodec copy -strict -2" + bitStreamArgs;
+            }
+
+            var args = "-codec:a:0 " + audioCodec;
+
+            var channels = state.OutputAudioChannels;
+
+            if (channels.HasValue)
+            {
+                args += " -ac " + channels.Value;
+            }
+
+            var bitrate = state.OutputAudioBitrate;
+
+            if (bitrate.HasValue)
+            {
+                args += " -ab " + bitrate.Value.ToString(CultureInfo.InvariantCulture);
+            }
+
+            if (state.OutputAudioSampleRate.HasValue)
+            {
+                args += " -ar " + state.OutputAudioSampleRate.Value.ToString(CultureInfo.InvariantCulture);
+            }
+
+            args += _encodingHelper.GetAudioFilterParam(state, _encodingOptions);
+
+            return args;
+        }
+
+        /// <summary>
+        /// Gets the video arguments for transcoding.
+        /// </summary>
+        /// <param name="state">The <see cref="StreamState"/>.</param>
+        /// <returns>The command line arguments for video transcoding.</returns>
+        private string GetVideoArguments(StreamState state)
+        {
+            if (state.VideoStream == null)
+            {
+                return string.Empty;
+            }
+
+            if (!state.IsOutputVideo)
+            {
+                return string.Empty;
+            }
+
+            var codec = _encodingHelper.GetVideoEncoder(state, _encodingOptions);
+
+            var args = "-codec:v:0 " + codec;
+
+            // Prefer hvc1 to hev1.
+            if (string.Equals(state.ActualOutputVideoCodec, "h265", StringComparison.OrdinalIgnoreCase)
+                || string.Equals(state.ActualOutputVideoCodec, "hevc", StringComparison.OrdinalIgnoreCase)
+                || string.Equals(codec, "h265", StringComparison.OrdinalIgnoreCase)
+                || string.Equals(codec, "hevc", StringComparison.OrdinalIgnoreCase))
+            {
+                args += " -tag:v:0 hvc1";
+            }
+
+            // if (state.EnableMpegtsM2TsMode)
+            // {
+            //     args += " -mpegts_m2ts_mode 1";
+            // }
+
+            // See if we can save come cpu cycles by avoiding encoding.
+            if (EncodingHelper.IsCopyCodec(codec))
+            {
+                // If h264_mp4toannexb is ever added, do not use it for live tv.
+                if (state.VideoStream != null && !string.Equals(state.VideoStream.NalLengthSize, "0", StringComparison.OrdinalIgnoreCase))
+                {
+                    string bitStreamArgs = EncodingHelper.GetBitStreamArgs(state.VideoStream);
+                    if (!string.IsNullOrEmpty(bitStreamArgs))
+                    {
+                        args += " " + bitStreamArgs;
+                    }
+                }
+
+                args += " -start_at_zero";
+            }
+            else
+            {
+                args += _encodingHelper.GetVideoQualityParam(state, codec, _encodingOptions, DefaultEncoderPreset);
+
+                // Set the key frame params for video encoding to match the hls segment time.
+                args += _encodingHelper.GetHlsVideoKeyFrameArguments(state, codec, state.SegmentLength, true, null);
+
+                // Currenly b-frames in libx265 breaks the FMP4-HLS playback on iOS, disable it for now.
+                if (string.Equals(codec, "libx265", StringComparison.OrdinalIgnoreCase))
+                {
+                    args += " -bf 0";
+                }
+
+                var hasGraphicalSubs = state.SubtitleStream != null && !state.SubtitleStream.IsTextSubtitleStream && state.SubtitleDeliveryMethod == SubtitleDeliveryMethod.Encode;
+
+                if (hasGraphicalSubs)
+                {
+                    // Graphical subs overlay and resolution params.
+                    args += _encodingHelper.GetGraphicalSubtitleParam(state, _encodingOptions, codec);
+                }
+                else
+                {
+                    // Resolution params.
+                    args += _encodingHelper.GetOutputSizeParam(state, _encodingOptions, codec);
+                }
+
+                if (state.SubtitleStream == null || !state.SubtitleStream.IsExternal || state.SubtitleStream.IsTextSubtitleStream)
+                {
+                    args += " -start_at_zero";
+                }
+            }
+
+            args += " -flags -global_header";
+
+            if (!string.IsNullOrEmpty(state.OutputVideoSync))
+            {
+                args += " -vsync " + state.OutputVideoSync;
+            }
+
+            args += _encodingHelper.GetOutputFFlags(state);
+
+            return args;
+        }
+    }
+}